Sad that you've ruined this movie, cause now I know of the flaw as well, lol. But that's something I'm certain I would have spotted as well. CCTV is literally the first thing anyone with two working brain cells check let alone the entire Police Force. Sad, but at least the other good elements in the film make this blunder permissible. Almost.
Heheh. Writing about plot flaws is impossible without spoilers.
Yeah, most people should spot it, though. Yeah, very permissible.